Question: $-uv - 7uw - 7u + 10 = -4v + 7$ Solve for $u$.
Combine constant terms on the right. $-uv - 7uw - 7u + {10} = -4v + {7}$ $-uv - 7uw - 7u = -4v - {3}$ Notice that all the terms on the left-hand side of the equation have $u$ in them. $-1{u}v - 7{u}w - 7{u} = -4v - 3$ Factor out the $u$ ${u} \cdot \left( -v - 7w - 7 \right) = -4v - 3$ Isolate the $u$ $u \cdot \left( -{v - 7w - 7} \right) = -4v - 3$ $u = \dfrac{ -4v - 3 }{ -{v - 7w - 7} }$ We can simplify this by multiplying the top and bottom by $-1$. $u= \dfrac{4v + 3}{v + 7w + 7}$